The present invention relates to apparatus for the working of articles, and more particularly to a novel method and apparatus for forming recesses or bores in articles, such as sticks of lumber.
In the building construction industry, it has been found particularly advantageous to provide bores in sticks of lumber, such as studs which are to be used for stud walls. Generally, it has been the practice to initially erect stud walls for a home or building and then drill holes or bores in the studs to accommodate electrical wiring, piping, etc. However, it is a time-consuming proposition to drill bores in the studs on a jobsite. Therefore, it has become apparent that a significant advantage would be to predrill bores in the studs prior to erection thereof. Such predrilling would most expeditiously be achieved at lumber mills producing the studs, but there are significant problems which must be overcome in order to provide a method and apparatus for predrilling studs which will not interfere with line production of lumber.
Accordingly, it is a general object of the present invention to provide a method and apparatus for simultaneously forming bores in articles, such as elongate sticks of lumber or studs which may be readily provided in a mill production line. More particularly, it is an object of the present invention to provide an apparatus including a conveying means, positioned downstream of, for example, trimmer saws, which is operable for transporting the studs to a drilling or work station. Disposed adjacent the work station, in accordance with the present invention, is a charging means operable for isolating a predetermined batch or course of the studs from the conveying means and maintaining the studs substantially stationary. Drilling means are suitably mounted on the charging means and beneath the course operable for selective shifting vertically upwardly for simultaneously drilling bores in each article of the course from the bottom surfaces thereof.
Another object of the present invention is to provide an apparatus, as described above, in which the charging means cooperates with a stabilizing means, such as an overhead hold down member disposed above the conveying means. More particularly, the charging means includes a lift means selectively operable for engaging and shifting the course upwardly from the conveying means and urging the course against the overhead hold down member to thereby clamp the course thereagainst. The lift means is incorporated within a carriage assembly which is selectively operable for reciprocal vertical shifting to lift the course from the conveying means and to also return the course thereto. The drilling means is rigidly mounted on the carriage assembly and movable therewith. Thus, when the course is clamped against the overhead hold down member, the drilling means may be further shifted during vertical movement of the carriage assembly for drilling bores into the course.
Still another object of the present invention is to provide a carriage assembly which includes a lift element and mounting means for connecting the lift element to the carriage assembly. The mounting means includes resilient means, such as air bags, which are interposed between the life element and the carriage assembly to enable the lift element to be raised, upon upward shifting of the carriage assembly, to a position whereby the lift element initially engages the course and continuously clamps it against the overhead member while simultaneously permitting subsequent relative shifting of the carriage assembly so that the drilling means engages and drills bores into the articles. The air bags, being compressible, permit the lift element to clamp the course against the overhead hold down member while permitting subsequent upward movement of the drilling means.
Thus, it can be appreciated that the apparatus of the present invention provides a method for forming bores in articles which includes grouping a predetermined batch or course of the articles and shifting the course vertically upwardly against an overhead stabilizing means to permit boring of the articles.
These and additional objects and advantages of the present invention will be more readily understood after a consideration of the drawings and the following detailed description of the preferred embodiment.